Notes:
- 1) The fitting includes the systematic errors.
- 2) When the burst includes telescope slew time periods, the fitting uses an average response file made from multiple 5-s response files through out the slew time plus single time preiod for the non-slew times, and weighted by the total counts in the corresponding time period using addrmf. An average response file is needed becuase a spectral fit using the pre-slew DRM will introduce some errors in both a spectral shape and a normalization if the PHA file contains a lot of the slew/post-slew time interval.
- 3) For fits to more complicated models (e.g. a power-law over a cutoff power-law), the BAT team has decided to require a chi-square improvement of more than 6 for each extra dof.
Time averaged spectrum fit using the average DRM
Power-law model
Time interval is from -38.296 sec. to 267.908 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.67658 ( -0.0894647 0.0884508 )
Norm@50keV : 1.92691E-03 ( -9.82413e-05 9.77392e-05 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 57.40 using 59 bins.
Reduced chi-squared = 1.00702
# Null hypothesis probability of 4.60e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 306.2 sec: 0.253868 ( -0.01247 0.012489 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.4744e-06 ( -2.95167e-07 2.97322e-07 ) ergs/cm2
Cutoff power-law model
Time interval is from -38.296 sec. to 267.908 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.11779 ( -0.372257 0.406674 )
Epeak [keV] : 76.2478 ( -14.5114 54.5881 )
Norm@50keV : 3.72630E-03 ( -0.00129912 0.00224334 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 50.57 using 59 bins.
Reduced chi-squared = 0.903036
# Null hypothesis probability of 6.80e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 306.2 sec: 0.245440 ( -0.013582 0.013597 ) ph/cm2/s
Energy fluence (15-150 keV) : 5.20326e-06 ( -3.40693e-07 3.43706e-07 ) ergs/cm2
1-s peak spectrum fit
Power-law model
Time interval is from 0.228 sec. to 1.228 sec.
Spectral model in power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -1.15841 ( -0.209287 0.211992 )
Norm@50keV : 1.50695E-02 ( -0.00189184 0.00189127 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 43.95 using 59 bins.
Reduced chi-squared = 0.771053
# Null hypothesis probability of 8.97e-01 with 57 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.75920 ( -0.22649 0.22691 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.5476e-07 ( -2.13311e-08 2.14619e-08 ) ergs/cm2
Cutoff power-law model
Time interval is from 0.228 sec. to 1.228 sec.
Spectral model in the cutoff power-law:
------------------------------------------------------------
Parameters : value lower 90% higher 90%
Photon index: -0.534878 ( -0.740117 1.05957 )
Epeak [keV] : 131.194 ( -51.502 -131.194 )
Norm@50keV : 2.92007E-02 ( -0.0135784 0.0564217 )
------------------------------------------------------------
#Fit statistic : Chi-Squared 42.45 using 59 bins.
Reduced chi-squared = 0.758036
# Null hypothesis probability of 9.09e-01 with 56 degrees of freedom
Photon flux (15-150 keV) in 1 sec: 1.72194 ( -0.23432 0.23305 ) ph/cm2/s
Energy fluence (15-150 keV) : 1.50702e-07 ( -2.27138e-08 2.24789e-08 ) ergs/cm2
Time-resolved spectra
